specify that extern c-variadic functions cannot be safe

folkertdev · folkertdev · commit 07d289f68b42 · 2025-06-03T23:35:59.000+02:00
diff --git a/src/items/external-blocks.md b/src/items/external-blocks.md
@@ -182,6 +182,10 @@ unsafe extern "C" {
 }
 ```
 
+r[items.extern.variadic.safety]
+A variadic extern function cannot be qualified as `safe`.
+Passing an unexpected number of arguments or arguments of an unexpected type to a variadic function is UB.
+
 r[items.extern.attributes]
 ## Attributes on extern blocks
 

Original file line number	Diff line number	Diff line change
`@@ -182,6 +182,10 @@ unsafe extern "C" {`
`182`	`182`	`}`
`183`	`183`	```
`184`	`184`
	`185`	`+r[items.extern.variadic.safety]`
	`186`	+A variadic extern function cannot be qualified as `safe`.
	`187`	`+Passing an unexpected number of arguments or arguments of an unexpected type to a variadic function is UB.`
	`188`	`+`
`185`	`189`	`r[items.extern.attributes]`
`186`	`190`	`## Attributes on extern blocks`
`187`	`191`